Can I password-protect a PDF online?

Yes. Upload one supported PDF, set an 8–128 character password, and select Protect PDF to create an AES-256 encrypted file.

Does Protect PDF use AES-256 encryption?

Yes. The current tool encrypts the PDF with AES-256 open-password protection.

What password length is supported?

Passwords must contain at least 8 characters and no more than 128 characters. Spaces are preserved as entered.

Can I protect an already password-protected PDF?

No. PDFs that are already encrypted are rejected by the current tool.

Can you recover my forgotten PDF password?

No. There is no password recovery or reset service for protected PDFs. Keep your password somewhere secure.

Does PDF password protection prevent copying?

Encryption requires the password to open the document, but it does not guarantee that content cannot be copied after an authorized user opens the PDF.

Is PDF protection the same as adding a watermark?

No. A watermark is a visible text overlay. Protect PDF encrypts the document so a password is required to open it.

Are printing and copying restrictions available?

No. The current tool provides open-password AES-256 encryption only and does not expose separate PDF permission settings.

Protect PDF

Add a password so the PDF cannot be opened without it. Encryption uses AES-256 from the PDF library — not a custom cipher. This is document open-password protection, not military-grade or DRM.

Choose a password of 8–128 characters. Spaces are kept exactly as typed. Already password-protected files cannot be protected again here. PDF permission flags are not offered: they are easy to ignore and would be misleading with a single password.

Drop a PDF here or browse One PDF. Up to 25 MB.

Password

Required to open the protected PDF. Not stored in your browser.

Confirm password

Must match exactly, including spaces.

What this tool does

Protect PDF encrypts one PDF with AES-256 so a password is required to open the protected document.

You choose the password yourself. Passwords can contain 8–128 characters and are kept exactly as entered, including spaces.

The protected download is named protected.pdf. Already encrypted PDFs cannot be protected again by this tool.

This is open-password PDF encryption, not DRM. Encryption helps restrict access to the document, but it cannot prevent every form of copying after someone legitimately opens the file.

How to use it

Upload one PDF that is not already encrypted. The maximum input size is 25 MB.
Enter a password between 8 and 128 characters and confirm it.
Select Protect PDF. The private worker encrypts the document with AES-256.
Download protected.pdf when processing finishes.
Open the protected PDF in a compatible PDF reader and enter the same password when prompted.
Keep a secure copy of your password. The service cannot recover a forgotten password.

Important limitations

Only open-password AES-256 encryption is supported.
Already encrypted PDFs are rejected and cannot be re-protected.
PDF permission controls such as disabling printing or copying are not available in the current version.
Encryption does not guarantee that content cannot be copied after an authorized user opens the document.
There is no password recovery or password reset mechanism for protected PDFs.
Each job accepts one PDF up to 25 MB.

Frequently asked questions

Can I password-protect a PDF online?: Yes. Upload one supported PDF, set an 8–128 character password, and select Protect PDF to create an AES-256 encrypted file.
Does Protect PDF use AES-256 encryption?: Yes. The current tool encrypts the PDF with AES-256 open-password protection.
What password length is supported?: Passwords must contain at least 8 characters and no more than 128 characters. Spaces are preserved as entered.
Can I protect an already password-protected PDF?: No. PDFs that are already encrypted are rejected by the current tool.
Can you recover my forgotten PDF password?: No. There is no password recovery or reset service for protected PDFs. Keep your password somewhere secure.
Does PDF password protection prevent copying?: Encryption requires the password to open the document, but it does not guarantee that content cannot be copied after an authorized user opens the PDF.
Is PDF protection the same as adding a watermark?: No. A watermark is a visible text overlay. Protect PDF encrypts the document so a password is required to open it.
Are printing and copying restrictions available?: No. The current tool provides open-password AES-256 encryption only and does not expose separate PDF permission settings.